/*
Copyright (c) 2007,2007 Elizeu Nogueira da R. Jr.

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, 
are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice, 
      this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice, 
      this list of conditions and the following disclaimer in the documentation 
      and/or other materials provided with the distribution.
    * Neither the name of the Elizeu Nogueira da R. Jr. nor the names of its 
      contributors may be used to endorse or promote products derived from this 
      software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


This package is based on HypersonicSQL, originally developed by Thomas Mueller.
and HSQLDB original developed by the HSQL Development Group
*/

package br.com.dreamsource.mobile.jmesql;

import br.com.dreamsource.mobile.jmesql.exceptions.SQLException;
import java.io.*;

class Row {
    private Object oData[];
    private Table  tTable;    // null: memory row; otherwise: cached table

    // only required for cached table
    static int     iCurrentAccess = 0;

    // todo: use int iLastChecked;
    int		   iLastAccess;
    Row		   rLast, rNext;
    int		   iPos;
    int		   iSize;
    boolean	   bChanged;
    private Node   nFirstIndex;

    Row(Table t, Object o[]) throws SQLException {
	tTable = t;

	int index = tTable.getIndexCount();

	nFirstIndex = new Node(this, 0);

	Node n = nFirstIndex;

	for (int i = 1; i < index; i++) {
	    n.nNext = new Node(this, i);
	    n = n.nNext;
	}

	oData = o;

	if (tTable != null && tTable.cCache != null) {
	    iLastAccess = iCurrentAccess++;

	    iSize = 8 + Column.getSize(o, tTable)
		    + 32 * tTable.getIndexCount();
	    iSize = ((iSize + 7) / 8) * 8;    // align to 8 byte blocks

	    tTable.cCache.add(this);
	}

	bChanged = true;
    }

    void cleanUpCache() throws SQLException {
	if (tTable != null && tTable.cCache != null) {

	    // so that this row is not cleaned
	    iLastAccess = iCurrentAccess++;

	    tTable.cCache.cleanUp();
	}
    }

    void changed() {
	bChanged = true;
	iLastAccess = iCurrentAccess++;
    }

    Node getNode(int pos, int index) throws SQLException {

	// return getRow(pos).getNode(index);
	Row r = tTable.cCache.getRow(pos, tTable);

	r.iLastAccess = iCurrentAccess++;

	return r.getNode(index);
    }

    private Row getRow(int pos) throws SQLException {
	return tTable.cCache.getRow(pos, tTable);
    }

    Node getNode(int index) {
	Node n = nFirstIndex;

	while (index-- > 0) {
	    n = n.nNext;
	}

	return n;
    }

    Object[] getData() {
	iLastAccess = iCurrentAccess++;

	return oData;
    }

    Row(Table t, DataInput in, int pos,
	    Row before) throws IOException, SQLException {
	tTable = t;

	int index = tTable.getIndexCount();

	iPos = pos;
	nFirstIndex = new Node(this, in, 0);

	Node n = nFirstIndex;

	for (int i = 1; i < index; i++) {
	    n.nNext = new Node(this, in, i);
	    n = n.nNext;
	}

	int l = tTable.getInternalColumnCount();

	oData = Column.readData(in, l);

	Trace.check(in.readInt() == iPos, Trace.INPUTSTREAM_ERROR);
	insert(before);

	iLastAccess = iCurrentAccess++;
    }

    void insert(Row before) {
	if (before == null) {
	    rNext = this;
	    rLast = this;
	} else {
	    rNext = before;
	    rLast = before.rLast;
	    before.rLast = this;
	    rLast.rNext = this;
	}
    }

    boolean canRemove() throws SQLException {
	Node n = nFirstIndex;

	while (n != null) {
	    if (Trace.ASSERT) {
		Trace.assert1(n.iBalance != -2);
	    }

	    if (Trace.STOP) {
		Trace.stop();
	    }

	    if (n.iParent == 0 && n.nParent == null) {
		return true;
	    }

	    n = n.nNext;
	}

	return false;
    }

    byte[] write() throws IOException, SQLException {
	ByteArrayOutputStream bout = new ByteArrayOutputStream(iSize);
	DataOutputStream      out = new DataOutputStream(bout);

	out.writeInt(iSize);
	nFirstIndex.write(out);
	Column.writeData(out, oData, tTable);
	out.writeInt(iPos);

	bChanged = false;

	return bout.toByteArray();
    }

    void delete() throws SQLException {
	if (tTable != null && tTable.cCache != null) {
	    bChanged = false;

	    tTable.cCache.free(this, iPos, iSize);
	}
    }

    void free() throws SQLException {
	rLast.rNext = rNext;
	rNext.rLast = rLast;

	if (rNext == this) {
	    rNext = rLast = null;
	}
    }

}
